How much grass seed do I need per square metre?
To cover one square metre, you need about 34.2 g of grass seed for a new lawn — a typical tall-fescue rate — or about 17.1 g to overseed a thin existing lawn. Across common grass types the new-lawn amount ranges from 7.3 g to 39.1 g.
Grass seed for one m², by grass type
| Grass type | New lawn (grams) | Overseeding (grams) |
|---|---|---|
| Tall Fescue | 34.2 g | 17.1 g |
| Kentucky Bluegrass | 12.2 g | 7.3 g |
| Perennial Ryegrass | 39.1 g | 19.5 g |
| Bermuda | 7.3 g | 4.9 g |
| Generic / mixed | 24.4 g | 12.2 g |
Rates are typical U.S. cooperative-extension ranges (mid-range), applied to 11 sq ft. Your seed bag's label is the authority — read it and adjust, and buy about 5–10% extra for edges and thin spots.
Frequently asked questions
How much grass seed do I need per square metre?
For one square metre, plan on about 34.2 g of grass seed for a new lawn, or about 17.1 g for overseeding, using a typical tall-fescue rate. The exact amount depends on the grass type — across common cool- and warm-season grasses the new-lawn figure ranges from 7.3 g to 39.1 g. Enter your real dimensions in the calculator above to get a number for your specific lawn and seed.
Does the grass type change how much seed I need for one m²?
Yes — a lot. Fine, spreading grasses like Kentucky bluegrass need far less than bunch grasses. For one m², a new lawn needs about 12.2 g of Kentucky bluegrass but about 39.1 g of perennial ryegrass. The table on this page lists every common grass type so you can match your seed bag.
How is the grass seed amount for one m² calculated?
Seed is applied at a rate in pounds per 1,000 square feet, so pounds = rate × (area ÷ 1,000). This page works from a one square metre basis; enter your own dimensions above — in feet, yards or metres — and the calculator does the arithmetic, including the metric conversion, for you.
Are these seeding rates exact?
They are typical U.S. cooperative-extension ranges, chosen mid-range and rounded for a planning estimate. Your seed bag's label is the real authority: it gives the exact rate for that blend and whether it is a new-lawn or overseeding rate. Always read the bag and adjust, and buy about 5–10% extra for edges and thin spots.
Grass seed for other sizes
For 1,000 sq ftFor 1 acreFor 2 acresFor ½ acreFor 100 m²Per square footTo overseed New lawn vs overseeding Full calculator →